[Rev 01] RFR: 6572: Make mbean functions protected by permission checks

[Jessye Coleman-Shapiro]

> This patch adds a permission check to Agent MBean functions for the 'control' management permission. 
> 
> I have also added a test "testPermissionChecks" to see if a security exception is fired when this permission is not given.

The pull request has been updated with 1 additional commit.

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Added commits:
 - d94062ca: Modify README description

Changes:
  - all: https://git.openjdk.java.net/jmc/pull/39/files
  - new: https://git.openjdk.java.net/jmc/pull/39/files/0e3ebef1..d94062ca

Webrevs:
 - full: https://webrevs.openjdk.java.net/jmc/39/webrev.01
 - incr: https://webrevs.openjdk.java.net/jmc/39/webrev.00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jmc/pull/39.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/39/head:pull/39

PR: https://git.openjdk.java.net/jmc/pull/39